Had the check engine light come on in my 2004 GMC truck with only 580 miles. Stopped by the dealer in Minot but he was too busy to take the time to check it. Between this time and the time I got to the dealer where I bought the truck in Mandan it had gone away.. aprox 200 miles later. They ran the diagnostic check on it and found out that it had tripped a turbo code. Their computer software isn't up to date enough to diagnose all the LLY codes. Seems the new turbo is computer controlled too or at least talks to the computer. Has anyone else had this problem????